The rm utility attempts to remove the non-directory
type files specified on the command line. If the permissions of the file do
not permit writing, and the standard input device is a terminal, the user is
prompted (on the standard error output) for confirmation.

Attempt to remove the files without prompting for
confirmation, regardless of the file's permissions. If the file does not
exist, do not display a diagnostic message or modify the exit status to
reflect an error. The -f option overrides any
previous -i options.

Request confirmation before attempting to remove each file,
regardless of the file's permissions, or whether or not the standard input
device is a terminal. The -i option overrides
any previous -f options.

Attempt to remove the file hierarchy rooted in each file
argument. The -R option implies the
-d option. If the
-i option is specified, the user is prompted
for confirmation before each directory (and its contents) are processed.
If the user does not respond affirmatively, the file hierarchy rooted in
that directory is skipped.

The rm utility removes symbolic links, not the
files referenced by the links.

It is an error to attempt to remove the root directory or the files
“.” or “..”. It is forbidden to remove the file
“..” merely to avoid the antisocial consequences of
inadvertently doing something like “rm -r
.*”.

The rm utility exits 0 if all of the named files or
file hierarchies were removed, or if the -f
option was specified and all of the existing files or file hierarchies were
removed. If an error occurs, rm exits with a
value >0.

The -P option assumes that both the underlying file
system and storage medium write in place. This is true for the FFS and MS-DOS
file systems and magnetic hard disks, but not true for most flash storage. In
addition, only regular files are overwritten; other types of files are
not.